Injection nozzle for liquid fuel

ABSTRACT

An injection nozzle for liquid fuel supplied under pulsating pressure and atomized at the nozzle opening formed between a fixed valve seat and a movable valve body which includes a fixed valve seat in the shape of a cone, a movable valve body of corresponding shape and an annular spring supported on the valve body at a distance from the nozzle opening. The nozzle opening is concentric with relation to the annular spring which supports the valve body in its cooperation with the valve seat.

United States Patent Graffman Jan. 29, 1974 [54] INJECTION NOZZLE FOR LIQUID FUEL FOREIGN PATENTS OR APPLICATIONS 1 I Johan m 9, 830,591 2/1952 Germany 239/533 Blomstersttgen, Danderyd, Sweden [22] Filed; Aug. 1972 Primary ExamineF-M. Henson Wood, Jr.

Assistant Examiner-Michael Y. Mar 1 PP Attorney, Agent, or Firm'Stevens, Davis, Miller &

. I Mosher [30] Foreign Application Priority Data Mar. 20, 1972 Sweden 3557/72 [57] ABSTRACT An injection nozzle for liquid fuel supplied under pu1- 52 US. Cl. 239/533, 267/15 Sating pressure and atomized at the nozzle Opening 51 Int. Cl Bosh 1/30 formed between a fixed valve Seat and a movable [58] Field of Search-M1. 239/D1G. 4, 533,453,456, valve body which includes a fixed valve Seat in the 239/459; 2 7/1 5 shape of a cone, a movable valve body of corresponding shape and an annular spring supported on the 5 l Cited valve body at a distance from the nozzle opening. The

UNITED STATES PATENTS nozzle opening is concentric with relation to the annular spring which supports the valve body in its cooper- 3,361,353 1/1968 Mlllman 239/533 X ation with the valveseat 3,297,260 1/1967 Barlow... 239/533 3,717,305 2/1973 Hedges 239/533 X 5 Claims, 2 Drawing Figures 1 INJECTION NOZZLE FOR LIQUID FUEL This invention relates to an injection nozzle for liquid fuel supplied under pressure to the nozzle and atomized at the nozzle opening by a spring movement between a valve body and a valve seat.

Injection nozzles of the aforesaid kind are now used in several connections, for example for the injection of fuel in internal-combustion engines. The injection nozzles have proved suitable in this connection, because the valve body abutting resiliently the valve seat by its vibratory movement brings about an effective atomization of the fuel. In said cases the fuel was supplied with a pulsating pressure, which has caused the valve body to vibrate to and from the valve seat.

There have, however, difficulties arisen to maintain the valve body in correct position. If the valve body is displaced from its correct axial position, the atomization deteriorates and the injected jet is given an incorrect shape. One has tried to overcome these deficiencies by designing the valve body rotation-symmetrically with respect to the flow conditions and thereby to uniformly distribute the pressure load on the valve body, which thereby would not be affected by lateral forces drawing the valve body out of its centered position. The proposed solutions, however, did not show satisfactory results. Even in those cases when a good atomization was achieved, it could easily be disturbed by the valve body having been displaced from its centered position.

The present invention has as its object to produce an injection nozzle, which does not give rise to the centering problem for the valve body. The solution of the problem is defined in the attached claims, and in thefollowing a specially suitable embodiment is described with reference to the accompanying drawings, in which FIG. 1 shows a lateral view of the injection nozzle in assembled state, and 7 FIG. 2 shows the main nozzle parts dismounted to the Side of each other.

' The nozzle comprises a valve housing 1 having a through axial channel for fuel supply. The fuel flows out through mouths 2 at the lower portion of the valve housing. Said lower portion is provided with a pinshaped member 3 terminating in a conical surface 11 in, which grooves 4 extend to the cone top. The conical surface 11 constitutes a valve seat for a valve body 5 which includes an inner sealing surface 12 of the same cone shape as the surface 11. The valve body 5 is formed as a sleeve portion adapted to be moved over the pin 3 with sufficient clearance between the inner surface of the sleeveportion and the outside of the pin 3 for allowing the feed of fuel from the months 2 to an aperture 6 in the valve body 5.

The valve body 5 has a collar 13 to which abuts an O-ring 8. Upon moving the valve body5 over the pin 3, the valve body 5 rests against the pin 3 as the inner sealing surface 12 in the valve body 5 abuts the valve seat surface 11 on the pin 3. For. maintaining the valve body 5 in position, the sleeve 7 is applied from below. The sleeve is provided with an internal annular shoulder 14 which engages with the O-ring 8. Upon screwing in the sleeve 7 against the valve housing 1, the valve body 5 is pressed by spring action from the O-ring 8 against the conical surface 11 of the pin 3. The pressing force shall not be strong, but can thus be adjusted by screwing the sleeve 7 more or less on the valve housing I. A threaded piece 15 and 16 in the sleeve 7 and, re-

supports the valve body in its cooperation with the v spectively, valve housing 1 establishes this connection. On the valve housing 1 an O-ring 9 is mounted which seals against the inside of the sleeve 7, and owing to the O-ring 8 the pin 3 and the interior of the valve body 5 are sealed outwards by the sleeve 7.

During operation, fuel is supplied through the axial channel 10 and flows out through the mouths 2. The fuel thereafter flows down along the pin 3 in the space between the pin 3 and the inside of the valve body 5. Between the conical surface 11 and the sealing surface 12 a clearance can be set which varies in response to the pressure of the fuel supplied and the spring properties of the O-ring 8. The fuel, thus, flows out through the aperture 6 with an amount determined by said clearance.

When the fuel is supplied with a pulsating pressure, the valve body 5 carries out axial reciprocating vibrations in response to the spring properties of the O-ring 8. Upon removal of the valve body 5 from the surface 1 1 due to spring action, fuel flows out through the nozzle aperture 6. Owing to the vibrations of the valve body 5 produced by the pulsating nature of the pressure in the fuel advanced, a good atomization is obtained. The O-ring 8 supporting the valve body 5 in a position spaced from the co-acting cone surfaces 11 and 12, the valve body 5 automatically is centered relative the fixed cone pin 3, and the annular opening about the cone point at the aperture 6 always remains uniform. Instead of an O-ring 8 another kind of spring may be used, for example a spring washer, in which case, however, the sealing between the valve body 5 and the sleeve 7 is to be given a different design. Also variations with respect to the mouths 2 may be made. In FIG. 2 the mouths are shown having axial direction, but it is suitable to provide the mouths with a radial directional componentand thereby to force the fuel to perform a screw line movement along the outside of the pin 3. The fuel when it passes the sealing surfaces and flows out through the aperture 6 is hereby given a rotational flow resulting in an improved and more uniform distribution of the fuel.

The invention has been described aboveby way of a special embodiment, but it'may be varied within the scope of the following claims. The valve body, for example, may be formed as a plane disc with a central bore and sealing against a plane surface, the fuel being led inwards to the centre between the disc and the sealing surface and out through the centralbore in the disc.

I claim:

1. An injection nozzle for liquid fuel supplied under pulsating pressure to the nozzle and atomized at the nozzle opening formed between a fixed valve seat and a .movble valve body, said nozzle opening being concentric in relation to an annular spring means, which the pin with a slight clearance and formed with an external edge, against which an annular spring abuts, said valve body and valve seat being enclosed by a sleeve tightly embracing said parts and resting on said spring, and said fuel being supplied to the valve seat in the gap between the pin and the sleeve portion.

mouths of which have a radial directional component. 5. The injection nozzle according to claim 3, wherein said spring is an O-ring abutting tightly the sleeve por- 4. The injection nozzle according to claim 2, wherein 5 tion of the valve body and the inside of the Sleevesaid fuel is supplied to the valve seat in channels, the 

1. An injection nozzle for liquid fuel supplied under pulsating pressure to the nozzle and atomized at the nozzle opening formed between a fixed valve seat and a movble valve body, said nozzle opening being concentric in relation to an annular spring means, which supports the valve body in its cooperation with the valve seat, said spring means having a supporting means on the valve body at a distance from said nozzle opening.
 2. The injection nozzle according to claim 1, wherein said valve seat has the shape of a cone directed in the injection direction, and has a corresponding sealing surface with a hole directly in front of the cone point.
 3. The injection nozzle according to claim 2, wherein said valve seat is formed at the end of a cylindric pin, and said valve body includes a sleeve portion enclosing the pin with a slight clearance and formed with an external edge, against which an annular spring abuts, said valve body and valve seat being enclosed by a sleeve tightly eMbracing said parts and resting on said spring, and said fuel being supplied to the valve seat in the gap between the pin and the sleeve portion.
 4. The injection nozzle according to claim 2, wherein said fuel is supplied to the valve seat in channels, the mouths of which have a radial directional component.
 5. The injection nozzle according to claim 3, wherein said spring is an O-ring abutting tightly the sleeve portion of the valve body and the inside of the sleeve. 